The prevalence of insulin resistance in glucose intolerant subjects has long been recognized. Reaven et al (American Journal of Medicine 1976, 60, 80) used a continuous infusion of glucose and insulin (insulin/glucose clamp technique) and oral glucose tolerance tests to demonstrate that insulin resistance existed in a diverse group of nonobese, nonketotic subjects. These subjects ranged from borderline glucose tolerant to overt, fasting hyperglycemia. The diabetic groups in these studies included both insulin dependent (IDDM) and noninsulin dependent (NIDDM) subjects. Coincident with sustained insulin resistance is the more easily determined hyperinsulinemia, which can be measured by accurate determination of circulating plasma insulin concentration in the plasma of subjects. Hyperinsulinemia can be present as a result of insulin resistance, such as is in obese and/or diabetic (NIDDM) subjects and/or glucose intolerant subjects, or in IDDM subjects, as a consequence of over injection of insulin compared with normal physiological release of the hormone by the endocrine pancreas.
The association of hyperinsulinemia with obesity and with ischemic diseases of the large blood vessels (e.g. atherosclerosis) has been well established by numerous experimental, clinical and epidemiological studies (summarized by Stout, Metabolism 1985, 34, 7, and in more detail by Pyorala et al, Diabetes/Metabolism Reviews 1987, 3, 463). Statistically significant plasma insulin elevations at 1 and 2 hours after oral glucose load correlates with an increased risk of coronary heart disease.
Since most of these studies actually excluded diabetic subjects, data relating the risk of atherosclerotic diseases to the diabetic condition are not as numerous, but point in the same direction as for nondiabetic subjects (Pyorala et al). However, the incidence of atherosclerotic diseases in morbidity and mortality statistics in the diabetic population exceeds that of the nondiabetic population (Pyorala et al; Jarrett Diabetes/Metabolism Reviews 1989,5, 547; Harris et al, Diabetes in America, Chapter 29, pp 1-48, 1985.)
The independent risk factors obesity and hypertension for atherosclerotic diseases are also associated with insulin resistance. Using a combination of insulin/glucose clamps, tracer glucose infusion and indirect calorimetry, it has been demonstrated that the insulin resistance of essential hypertension is located in peripheral tissues (principally muscle) and correlates directly with the severity of hypertension (DeFronzo and Ferrannini, Diabetes Care 1991, 14, 173). In hypertension of the obese, insulin resistance generates hyperinsulinemia, which is recruited as a mechanism to limit further weight gain via thermogenesis, but insulin also increases renal sodium reabsorption and stimulates the sympathetic nervous system in kidneys, heart, and vasculature, creating hypertension.
It is now appreciated that insulin resistance is usually the result of a defect in the insulin receptor signaling system, at a site post binding of insulin to the receptor. Accumulated scientific evidence demonstrating insulin resistance in the major tissues which respond to insulin (muscle, liver, adipose), strongly suggests that a defect in insulin signal transduction resides at an early step in this cascade, specifically at the insulin receptor kinase activity, which appears to be diminished (reviewed by Haring, Diabetalogia 1991, 34, 848).
Protein-tyrosine phosphatases (PTPases) play an important role in the regulation of phosphorylation of proteins. The interaction of insulin with its receptor leads to phosphorylation of certain tyrosine molecules within the receptor protein, thus activating the receptor kinase. PTPases dephosphorylate the activated insulin receptor, attenuating the tyrosine kinase activity. PTPases can also modulate post-receptor signaling by catalyzing the dephosphorylation of cellular substrates of the insulin receptor kinase. The enzymes that appear most likely to closely associate with the insulin receptor and therefore, most likely to regulate the insulin receptor kinase activity, include PTP1B, LAR, PTPα and SH-PTP2 (B. J. Goldstein, J. Cellular Biochemistry 1992, 48, 33; B. J. Goldstein, Receptor 1993, 3, 1-15,; F. Ahmad and B. J. Goldstein Biochim. Biophys Acta 1995, 1248, 57-69).
McGuire et al. (Diabetes 1991, 40, 939), demonstrated that nondiabetic glucose intolerant subjects possessed significantly elevated levels of PTPase activity in muscle tissue vs. normal subjects, and that insulin infusion failed to suppress PTPase activity as it did in insulin sensitive subjects.
Meyerovitch et al (J. Clinical Invest. 1989, 84, 976) observed significantly increased PTPase activity in the livers of two rodent models of IDDM, the genetically diabetic BB rat, and the STZ-induced diabetic rat. Sredy et al (Metabolism, 44, 1074, 1995) observed similar increased PTPase activity in the livers of obese, diabetic ob/ob mice, a genetic rodent model of NIDDM.
U.S. Pat. No. 6,211,244-B1 discloses aryl substituted amine derivatives of the following formula which are useful as inorganic ion receptor modulators for inhibition of bone resorption and treatment of hyperparathyroidism, Paget's disease, hypercalcemic disorders, osteoporosis, hypertension, and renal dystrophy. U.S. Pat. No. 6,211,244-B1 claims that at least one of R11 or R12 is methyl, and Ar5 does not specifically contain a naphthoic acid.
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JP 2000178243 discloses biphenylamidine derivatives of the following formula which are inhibitors of blood coagulation and are useful for preventing and treating thrombosis and embolism. JP 2000178243 discloses that the structure specifically contains amidino group (A1), Y1 does not specifically contain a naphthoic acid, and m,n are undefined. 
WO 200021920 discloses diaminopropionic acid derivatives of the following formula which are useful as ICAM-1 (intracellular adhesion molecule-1) antagonists for the treatment of rheumatoid arthritis, psoriasis, multiple sclerosis, Crohn's disease, and ischemic reperfusion injury. WO 200021920 claims that R1 can be a substituted naphthylene and R2 can be a methylene-amide linkage. 
EP 0919541-A1 discloses naphthalenic compounds of the following formula which are melatonin receptor agonists and antagonists useful in the treatment of circadian rhythm disorders, seasonal depression, cardiovascular disorders, appetite disorders, and obesity. EP 0919541-A1 claims that G2 is either an amide, thioamide, urea, or thiourea. 
WO 9511221 discloses arylalkylamine derivatives of the following formula which are useful as inorganic ion receptor modulators for treating diseases or disorders by altering inorganic ion receptor activity, preferably calcium receptor activity. WO 9511221 discloses at least one benzylic methyl group substitution, and when two X's equal a fused aromatic group, the patent does not specifically claim a naphthoic acid. 
The compounds of this invention have been shown to inhibit PTPaes derived from human-derived recombinant PTPase-1B (hPTP-1B) in vitro. They are useful in the treatment of insulin resistance associated with obesity, glucose intolerance, diabetes mellitus, hypertension and ischemic diseases of the large and small blood vessels.